The subject matter disclosed herein relates to gas turbine engines, and more specifically, to systems and methods for operating gas turbine engines.
Gas turbine engines are used in a wide variety of applications, such as power generation, aircraft, and various machinery. Gas turbine engines generally combust a fuel with an oxidant (e.g., air) in a combustor section to generate hot combustion products, which then drive one or more turbine stages of a turbine section. In turn, the turbine section drives one or more compressor stages of a compressor section. Again, the fuel and oxidant mix in the combustor section, and then combust to produce the hot combustion products. Under certain conditions, it may be desirable for the hot combustion products to have a low concentration of oxygen, carbon monoxide, nitrogen oxides, unburned hydrocarbons, or any combination thereof. Thus, it may be useful to use feedback control to operate the gas turbine engine to achieve a desired composition of the hot combustion products. Furthermore, gas turbine engines typically consume a vast amount of air as the oxidant, and output a considerable amount of exhaust gas into the atmosphere. In other words, the exhaust gas is typically wasted as a byproduct of the gas turbine operation. Unfortunately, utilizing flow meters to measure the vast amount of air as the oxidant may affect the air flow, as well as may increase system costs and system complexity.